Field of the Invention
The invention relates to a method of determining a mass of fuel to be introduced into a suction pipe or into a cylinder of an internal combustion engine, through the prescription of a combustion air ratio in the cylinder.
Air mass-guided motor control systems for internal combustion engines need to know the mass of fresh air flowing into the cylinder, in addition to the rotational speed, for the calculation of the injection time. A basic injection time is stored in a characteristic map as a function of those two variables. In order to take into account the most diverse operating states of the internal combustion engine, such as, for example, starting, warming up, full load, overrun operation, etc., during the calculation of the injection time, various additive and/or multiplicative correction factors act on the basic injection time, with the result that at the end of the correction chain it is no longer known what combustion air ratio is being realized in the cylinder by the driving of the injection valves.
In the case of internal combustion engines, a defined combustion air ratio is intended to be set as a function of the operating point.